The challenge for nullity of the arbitral award pursuant to art. 829 cod. proc. civ. constitutes proceedings of limited review, in which the Court of Appeal may not make findings of fact nor re-examine the merits of the dispute decided by the arbitrators, but may only ascertain the existence of the defects exhaustively prescribed by law.
The grounds for the challenge of the arbitral award for nullity must be specific, the applicant being required to identify precisely the defect complained of and the reasons for which it would vitiate the arbitral award, by analogy with the requirements laid down for appeals by art. 342 cod. proc. civ.
The challenge for nullity of the arbitral award comprises two phases: the rescinding phase, directed at ascertaining the existence of the defect complained of, and the substitutive phase, in which the Court of Appeal, having established the defect, decides the merits of the dispute, save in cases where the defect entails a remission to the arbitrators.
In proceedings on an appeal in cassation against the judgment rendered on the challenge of the arbitral award, the Court of Cassation may not proceed to a direct examination of the arbitral award, its review being limited to ascertaining the lawfulness of the judgment of the Court of Appeal.
An error in procedendo in arbitral proceedings, relevant pursuant to art. 829 co. 1 cod. proc. civ., must be distinguished from an error in iudicando, relevant pursuant to art. 829 co. 3 cod. proc. civ., inasmuch as only the former pertains to the modus procedendi of the arbitrators, whereas the latter concerns the breach of rules of substantive law applicable to the merits of the dispute.
Pursuant to art. 816-bis co. 1 cod. proc. civ., the parties may determine the rules to be observed by the arbitrators in the proceedings; in default thereof, the arbitrators have the power to regulate the conduct of the proceedings in the manner they consider most appropriate, in compliance with the principle of due process.
The challengeability of the arbitral award for breach of rules of law relating to the merits of the dispute, pursuant to art. 829 co. 3 cod. proc. civ., must be expressly provided for by the parties in the arbitration agreement or by the applicable law, failing which it is excluded.
The interpretation of the arbitration agreement (submission agreement or arbitration clause) is reserved to the court of merit and is not reviewable on appeal in cassation, save within the limits of a breach of the interpretive criteria set out in artt. 1362 et seq. cod. civ. or of a defect of reasoning.
The inconsistency of the arbitral award relevant pursuant to art. 829 co. 1 n. 11 cod. proc. civ. is to be understood in the sense that the conflict must emerge between the several components of the operative part or between the reasoning and the operative part, whereas an internal contradiction between the several parts of the reasoning does not constitute an autonomous defect, but only where it renders it absolutely impossible to reconstruct the logical and legal reasoning underlying the decision.